Fukushima Update #72 – December 5, 2011
by Nelle Maxey
The water decontamination system at the Fukushima plant site developed a leak on the weekend.
ENENews covers this well. . .with conversion factors and links to many other stories in Japanese press, New York Times and Wall Street Journal here:
5.8 trillion becquerels of strontium leaked from Fukushima over weekend
NHK: "The water is believed to have contained 130,000 becquerels per cubic centimeter of radioactive strontium."
- New York Times: "Tepco said a check on Saturday had found no sign of the leak, suggesting that it began Saturday night or early Sunday morning. The company said it was exploring ways to stop any more water from escaping."
- WSJ: New Leak Detected at Fukushima Plant — Asahi: Strontium at 1,000,000 times gov't limit?
- Japan Times: Tepco's decontamination system doesn't remove strontium — Media butchers details on latest Fukushima leak
Here is the full Tepco press release. It appears it is the desalination portion of the system that sprang the leak.
At 11:33 am on December 4, workers found that there was puddle water inside the barrier around the evaporative condensation apparatus (estimated volume of water was approx. 45 m3). At 11:52 am, we stopped the apparatus, and at 12:14 pm, workers made visual inspection of the apparatus and the leakage seemed to have stopped. After that, we conducted investigation at 2:30 pm, and found a crack in the concrete barrier, and water leaking from this crack to the gutter (surface dose rate of leaked water: beta ray 110 mSv/h, gamma ray 1.8 mSv/h).
We also found water leaking from between the barrier and the base concrete. We are considering measures to stop this leakage to outside of the barrier. The water desalination apparatus (reverse osmosis membrane type) is continuing operation. As we have sufficient volume of desalinated water, there is no impact on the Reactor water injection. At 3:30 pm we confirmed that the leakage had stopped by piling up sandbags between the barrier and base concrete, and in the gutter. From 6:20 pm to 10: 20 pm we sent the leaked water remaining in the barrier to the waste water RO supply tank with a water pump. Since the gutter led to the generally used channel of the power plant, we have taken sea water from the channel around the water desalinations (evaporative concentration apparatus) and the south drain (drain for the generally used channel) and have conducted a nuclide analysis. We concluded that the figures of the results of the analysis were as same or slightly higher than the usual results we are announcing daily.
Of course we know they are already using radioactive ash as ‘FILL' in the ocean in Tokyo, but now…
Japan: Scientists Call for Dumping Radioactive Soil Into Sea
December 5th, 2011
Via: Asahi:
Scientists have proposed dumping soil contaminated by radiation from the Fukushima nuclear disaster into the deep sea, an idea certain to meet opposition both at home and abroad.
A group led by Isao Tanihata, a professor at Osaka University's Research Center for Nuclear Physics, and Kozi Nakai, a former professor at the Tokyo University of Science, said the best way to get rid of the radioactive soil is to place it in noncorrosive, pressure-tight vessels and dumping them at least 2,000 meters deep near Japan.
"The sea, away from all residents, would pose no problem," Tanihata told about 30 researchers at a study meeting at Osaka University on Dec. 3.
The participants, including nuclear physicists and researchers at the Japan Atomic Energy Agency, did not object to the proposal from a scientific point of view.
But former education minister Akito Arima, who was also present, said, "The sea is common property of all humankind, and the key is whether fishermen and the general public will support the proposal."
Tanihata and Nakai, who have been involved in compiling the science ministry's soil contamination map, drafted the proposal as the government faces difficulties finding a final disposal site for soil contaminated with radioactive materials from the crippled Fukushima No. 1 nuclear power plant.
The group plans to submit a formal proposal to the government.
But it will be difficult to realize the project partly because dumping contaminated soil into the sea could constitute a violation of the London Convention, designed to prevent marine pollution.
TEPCO told to probe radioactive water leak
Japan's nuclear agency has ordered the operator of the Fukushima Daiichi nuclear plant to explain the cause of the latest leakage of radioactive water into the ocean, and what measures will be taken to prevent a recurrence.
Officials from the Nuclear and Industrial Safety Agency inspected the situation on Monday.
Tokyo Electric Power Company discovered on Sunday that at least 45 tons of radioactive water had leaked from a purification device at the plant. The utility says the water leaked through a cracked wall of the building into a gutter that drains into the Pacific Ocean.
TEPCO says it took workers about 21 hours before they noticed the leak.
The utility says the contaminated water contained radioactive cesium. It also contained levels of radioactive strontium that could pose health risks in case of internal exposure.
TEPCO says it will take at least two weeks to analyze the strontium level in the water.
The fisheries cooperative associations in Fukushima lodged a protest with Tokyo Electric Power over the leakage.
The federation told NHK on Monday that it demanded that the utility quickly determine the level of contamination in the area affected.
Monday, December 05, 2011 20:54 +0900 (JST)